The present invention relates to an operating device for a lock and, more particularly, to an operating device for a panic exit door lock that can be operated from an outer side of a door.
Locks for panic exit doors are widely utilized in panic exits and passageways in apartments, buildings, etc. To allow easy opening of the panic exit door in the case of emergency such as fire, an operating device with a larger operating surface is mounted to a side of the door for easily and rapidly unlocking the lock. Various operating devices have been developed according to differing user needs.
FIG. 11 shows a panic exit door lock 144 mounted to an inner side 140 of a door 136 and an operating device 152 mounted to an outer side 138 of door 136. A receiving space 142 extends from inner side 140 through outer side 138 of door 136. Panic exit door lock 144 includes a base 146 fixed to inner side 140 of door 136. A slide 148 is slideably mounted on base 146. A latch 150 is pivotably mounted to base 146 and operably connected to slide 148, such that movement of slide 148 causes movement of latch 150 between an extended, locking position and a retracted, unlocking position.
Operating device 152 includes a mounting plate 154 fixed to outer side 138 of door 136. A handle 156 is fixed to an outer face of mounting plate 154. A frame 158 is mounted to an inner face of mounting plate 154 and received in receiving space 142. Frame 158 includes two sidewalls 160 between which a lever 162 is pivotably mounted. Specifically, lever 162 includes a first end 164 outside of door 136, a second end 166 extending out of receiving space 142 and abutting slide 148, and an intermediate section 168 intermediate first and second ends 164 and 166 and pivotably mounted between sidewalls 160 of frame 158. A spacing D1 between a pivot axis of lever 162 to the force applying point at first end 164 of lever 162 is generally smaller than a spacing D2 between the pivot axis of lever 162 to the contact point between slide 148 and second end 166 of lever 162, such that a smaller displacement of lever 162 causes a longer displacement of slide 148 for unlocking purposes. However, a user has to apply a large force to move slide 148, which is not labor-saving while operating lever 162. On the other hand, spacing D1 can be made larger than spacing D2 to obtain a force-saving effect. However, reduction of spacing D2 is difficult, because spacing D2 must be large enough so that second end 166 of lever 162 can abut slide 148. Namely, lever 162 must protrude out of door 136 to a large extent for obtaining the force-saving effect without reducing spacing D2, leading to inconvenient operation of lever 162. Furthermore, lever 162 may be inadvertently impinged.
Thus, a need exists for an operating device for a lock that allows easy unlocking operation with less effort and without the risk of inadvertent operation.